A genuine OEM holding tank dump cap with built-in measuring cup for Thetford cassette toilets. Designed to replace the standard cap and double as a dosing cup for toilet chemicals, making it easier to maintain proper fluid levels and avoid spill-overs.

For hygiene and convenience, having a dual-use cap allows you to measure chemical additives accurately and dump waste without needing extra tools. Ideal for keeping your cassette toilet clean and efficient.

OEM Part Number: T25810-78 / 2581078 

Kit Includes:

• 1 × Dump/dump-cap cap with pour-out spout

• Built-in measure (cup) inside cap for chemical dosing

Compatability:

Suits Thetford C2, C3, C4, C200, C-200 CW and C-200 CWE cassette toilets

Colour / Finish: Yellow (cap & measuring markings) with grey spout-cap

Frequently Asked Questions

Q: What does this part replace or do?
It replaces the standard dump cap on compatible Thetford cassettes. It acts as a sealing cap and also a measuring cup for adding toilet chemical or fluid.

Q: Why is having a measuring cup useful?
It ensures you use the right amount of chemical additive — too little won’t be effective, too much is wasteful. Also minimizes risk of over-pouring/dripping when adding chemicals or dumping.

Q: What should I check before ordering?

Confirm the colour.

Q: How do I install / use it?
Screw it in place of the original cap. To use the measuring feature, pour chemical into the cap up to the marked fill line, then pour into the holding tank via the spout.