Pos-T-Vac Twist Cylinder — Standard & Large Replacement Cylinders

By Timm Medical / Pos-T-Vac  |  For Twist-Lock Pos-T-Vac Systems Only  |  Acrylic Construction

Standard: 2" × 8"  |  Large: 10" × 2.25" (includes large loading cone)  |  Twist-Lock Connection  |  Replacement or Upgrade  |  Ships Discreetly

Replacement acrylic cylinders for Pos-T-Vac vacuum erection systems with twist-lock pump head connections. The cylinder is the acrylic tube that fits over the penis to create the vacuum chamber — it attaches to the pump head and is the primary structural component of the VED system. When a cylinder cracks, becomes cloudy from repeated use, or requires replacement for any reason, this is the OEM Timm Medical replacement part. Also used by men who want to add a larger cylinder to their existing twist system without purchasing a complete new kit.

Two sizes are available. The standard 2"×8" cylinder is included with most Pos-T-Vac twist systems and fits the large majority of users. The large 10"×2.25" cylinder is for men who need additional room in the cylinder for comfort or for a more effective vacuum seal, and includes a large loading cone. Both are made from durable acrylic and are manufactured by Timm Medical / Pos-T-Vac.

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Size Options

Option	Cylinder Dimensions	Includes	Best For
Standard Twist Cylinder	2" diameter × 8" length	Cylinder only	Replacement for most Pos-T-Vac twist systems; fits the large majority of users
Large Twist Cylinder	2.25" diameter × 10" length	Cylinder + large loading cone	Men who need additional cylinder room for comfort or effective vacuum seal

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Twist vs. Slip — Critical Compatibility Information

Pos-T-Vac manufactures two distinct cylinder connection types that are not interchangeable:

Connection Type	How It Works	Compatible Systems
Twist (this product)	Cylinder locks onto pump head by twisting — creates a mechanically secured, airtight connection	Automatic 3000 (BOS-3) · Automatic 2000 (BOS-2) · Manual 3000 (V113) · Manual 2000 · Other twist-compatible Pos-T-Vac systems
Slip (not this product)	Cylinder slides onto pump head by friction — push-in connection	MVP 700 (M114) · Older Pos-T-Vac slip models

How to confirm your connection type: Look at the base of your current cylinder where it connects to the pump head. A twist cylinder has a locking channel or tabs that engage when rotated; a slip cylinder is a smooth push-on fit. If you can't determine your type from inspection, look at your model number — see the compatible systems table above. If still unsure, call us at 866-218-0902 before ordering.

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Key Features

• OEM Timm Medical replacement — exact fit for compatible systems — this is the original equipment manufacturer cylinder produced by Timm Medical for Pos-T-Vac twist systems; it matches the specifications of the cylinder included in the original kit, ensuring the same fit, vacuum performance, and pump-head connection quality as the original component
• Durable acrylic construction — the acrylic cylinder is transparent, allowing the user to see the erection developing inside during therapy; acrylic provides good impact resistance for regular daily use and is easy to clean; the material is the same used in the original Pos-T-Vac kits
• Twist-lock connection — superior seal — the twist-lock mechanism (as used in the Automatic 3000 and other premium Pos-T-Vac systems) creates a mechanically secured connection between the cylinder and pump head that maintains its seal more consistently under high vacuum than friction-based slip connections; replacing a worn or damaged twist cylinder with a new OEM part restores the full seal integrity of the system
• Large cylinder option — with large loading cone included — the large 10"×2.25" cylinder accommodates men for whom the standard 2"×8" cylinder is too tight for comfortable use or effective vacuum creation; the large cylinder comes with a large loading cone appropriate for its wider opening; if the standard cylinder creates a good vacuum but feels restrictive, or if vacuum consistency has been an issue with the standard size, the large cylinder is worth considering
• Cylinder replacement extends system life — the pump head and pump mechanism of a Pos-T-Vac system typically outlast the cylinder; replacing just the cylinder is more economical than purchasing a complete new kit when the pump mechanism is still functioning correctly

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When to Replace Your Cylinder

• Visible cracks, chips, or scratches on the cylinder surface that could affect the vacuum seal or cause discomfort
• Cloudiness or discoloration that makes it difficult to see inside during therapy
• Cylinder no longer seals to the pump head consistently despite the pump head functioning normally
• Cylinder was damaged during transport, loading, or storage
• Upgrading from standard to large cylinder size

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FAQs

How do I know if my system is a twist or slip?

The easiest way is to look at your pump head and current cylinder connection. A twist connection has a locking mechanism — you rotate the cylinder to lock and unlock it from the pump head. A slip connection slides straight on and off without rotation. If you're not sure by inspection, check your system's model number against the compatibility table above. The Automatic 3000 (BOS-3), Automatic 2000 (BOS-2), and Manual 3000 (V113) all use twist connections. The MVP 700 (M114) uses a slip connection. If still uncertain, call us at 866-218-0902 before ordering — ordering the wrong connection type means a non-functional part and a return.

Does the large cylinder come with a loading cone?

Yes — the large 10"×2.25" twist cylinder includes a large loading cone. The large loading cone is needed because the wider cylinder opening requires a proportionally larger cone for tension ring placement. The standard loading cone included with most Pos-T-Vac kits will not work correctly with the large cylinder.

Can I use my existing bushings with the large cylinder?

Bushings for the large cylinder are not included and are sold separately. The standard bushings included with most Pos-T-Vac kits are sized for the standard 2"×8" cylinder and are not appropriate for the large cylinder. If you are upgrading to the large cylinder, contact us to confirm which bushing size is appropriate for your anatomy with the larger bore: 866-218-0902.

How discreet is shipping?

All orders ship in plain, unmarked outer packaging with no reference to the product category or website on the exterior.

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Not sure which cylinder to order? Call before purchasing.
Call 866-218-0902  |  Support@medicaldepartmentstore.com  |  All inquiries handled discreetly.