Bascially, similar item as https://tappairsoft.com/product/tapp-mws-drum/  or https://www.powair6.com/en/hpa-magazine/15673-p6-400rds-hpa-drum-magazine-for-tokyo-marui-mws-m4-gbbr.html

This one of mine is 1000 rds drum,  it is build with original m4 gbb mag and battleaxe m4 drum.  So it will fit for any tm mws m4 system (tm mk18 gbb , tm m4a1 gbb,  tm urgi gbb anything tm m4/ar platform really),  make your mws m4 gun more practical to play in field

price is £200 including shipping (UK only)

P.S   I will not use paypal business/purchase/service transfer, as lost two expensive guns before in 2022. nearly £1000 gone, paypal wont do a sh** to help me.
 Buyer can claim back to refund regardless seller provides receipt or not..
So , definitely no paypal, and I am absolutely no rush to sell this, if buyer is really serious and interested in this item, I prefer local pick up from RM10 , and test in my garden to avoid any potential future issue,  
Or bank transfer (yup, just trust me at your own risk, unfortunately I have to say the word 'at your own risk' , if you do not trust me or insist go paypal,  please do not contact me)

Or Paypal F&F mode