I have 2x knock off cable releases that work ok. One of them good submerged under water (accident), and quit working for a few hours. Then it started working just as new. I then decided to order a back-up so in case this happened again.
Just pay shipping, which should be like $3 (have to buy bubble wrap and envelope).
Also have a 58mm Cokin P adapter ring. $1 to ship I would think. Also have an empty SD card case.